Issue if an extension add an element between field and dropdownmenu

[hguenot]

Helllo

I have an extension (F-Secure) that sometimes add an element between the field and the dropdown after Autocomplete initialization.

Every time, in the code, this.field.nextSibling is used to get the drop down menu, it fails because it references this extension element... and the dropdown menu display is broken

To fix this issue I opened a pull request (#30).
I just add a property to save the dropdown element in the Autocomplete class and used it instead of this.field.nextSibling

[cjauvin]

Hello, sorry for the delay, I will try to look at your issue and PR shortly!